Overview
Enamel and dentin fractures are common clinical challenges that can significantly impact the longevity and functionality of dental restorations. Proper diagnosis and management are crucial to ensure successful treatment outcomes and prevent recurrent fractures. This guideline synthesizes evidence from various studies to provide clinicians with a comprehensive approach to diagnosing and managing fractures involving enamel and dentin, emphasizing the importance of adhesive techniques and material selection in achieving durable restorations.
Diagnosis
Accurate diagnosis of enamel and dentin fractures is essential for effective treatment planning. Conventional methods such as shear bond strength (SBS) tests provide valuable insights but may not fully capture the long-term performance of dental restorations. Fatigue testing methods, as highlighted by studies [PMID:19679342], offer a more comprehensive evaluation by simulating real-world conditions over extended periods. These tests can help identify potential failure points in resin composite to enamel bonds, guiding clinicians in assessing the durability of existing restorations and predicting future issues.
Bond strength variability across different adhesive systems further complicates diagnosis. Research by [PMID:17427826] reveals consistent bond strengths for most adhesives across superficial and deep dentin, with notable exceptions like AQ Bond, which consistently performs poorly. This knowledge is crucial for clinicians to anticipate potential weaknesses in bonding, particularly when using less reliable adhesive systems. Kanca's work [PMID:9545912] underscores the necessity of assessing bond strength under varied clinical conditions, such as moisture levels and different etching protocols, to ensure reliable diagnosis and treatment planning. Understanding these factors helps in identifying which restoration techniques are likely to fail and require intervention.
Management
Effective management of enamel and dentin fractures involves meticulous selection and application of adhesive techniques and materials to ensure robust bonding. Phosphoric acid etching, as demonstrated by studies [PMID:30799475], significantly enhances bond strengths, particularly for enamel surfaces, when using universal adhesives like Scotchbond Universal, Prime & Bond Elect, and All-Bond Universal in etch-and-rinse modes. Clinicians should prioritize acid etching to achieve mean bond strengths exceeding 30 MPa, which are critical for long-term stability of restorations.
Thermal cycling (TC) is another critical factor influencing bond durability. While most universal adhesives maintain their bond strengths through TC [PMID:30799475], exceptions like iBond Universal show reduced bond strength post-TC. This variability necessitates careful consideration of adhesive choice based on the anticipated thermal stresses in a patient's oral environment. For instance, in patients with significant temperature fluctuations due to dietary habits or environmental factors, selecting adhesives with proven resilience under TC conditions is advisable.
Long-term durability is also a significant concern, as evidenced by studies [PMID:20178215]. All-in-one adhesives and Resulcin Aqua Prime exhibit significant reductions in bond strength over 6 months to 1 year, indicating the need for clinicians to consider the longevity of their chosen adhesive systems. Regular follow-up and potential reinforcement of restorations may be necessary to maintain structural integrity, especially in high-risk patients or restorations subjected to heavy occlusal forces.
The impact of clinical techniques, such as bonding to dry versus moist surfaces, cannot be overlooked. Fatigue testing by [PMID:19679342] shows that while Adper Single Bond Plus (SBP) and OptiBond Solo Plus (OBP) exhibit similar SBS to both moist and dry enamel, SBP demonstrates superior shear fatigue limits on dry enamel. This suggests that ensuring a dry bonding surface can enhance the long-term durability of restorations, particularly in challenging clinical scenarios.
Pre-etching enamel with phosphoric acid, as studied by Erickson RL et al. [PMID:19473695], significantly improves the bond strength of self-etch adhesives, narrowing the gap with etch-and-rinse adhesives. This technique can be particularly beneficial in clinical settings where simplifying the bonding procedure is desirable without compromising strength. Clinicians should consider pre-etching as a strategy to enhance bond durability, especially in cases involving enamel and dentin fractures where robust bonding is paramount.
Adhesive system selection should also be guided by specific clinical needs. Single Bond, as noted by [PMID:17427826], offers superior SBS to enamel compared to other systems like AQ Bond and Clearfil SE Bond, making it preferable for enamel bonding tasks. For deep dentin bonding, Clearfil SE Bond stands out due to its superior bond strength, thus being a preferred choice for deep cavity preparations. Kanca's evaluation of a novel one-step adhesive [PMID:9545912] indicates comparable bond strengths to etched enamel, suggesting its potential for simplifying procedures while maintaining efficacy, which can be advantageous in clinical settings where efficiency is crucial.
Key Recommendations
By integrating these diagnostic insights and management strategies, clinicians can enhance the prognosis of restorations involving enamel and dentin fractures, ensuring better patient outcomes and satisfaction.
References
1 Jacker-Guhr S, Sander J, Luehrs AK. How "Universal" is Adhesion? Shear Bond Strength of Multi-mode Adhesives to Enamel and Dentin. The journal of adhesive dentistry 2019. link 2 Osorio R, Monticelli F, Moreira MA, Osorio E, Toledano M. Enamel-resin bond durability of self-etch and etch & rinse adhesives. American journal of dentistry 2009. link 3 Barkmeier WW, Erickson RL, Latta MA. Fatigue limits of enamel bonds with moist and dry techniques. Dental materials : official publication of the Academy of Dental Materials 2009. link 4 Erickson RL, Barkmeier WW, Kimmes NS. Bond strength of self-etch adhesives to pre-etched enamel. Dental materials : official publication of the Academy of Dental Materials 2009. link 5 Yazici AR, Celik C, Ozgünaltay G, Dayangaç B. Bond strength of different adhesive systems to dental hard tissues. Operative dentistry 2007. link 6 Kanca J. One step bond strength to enamel and dentin. American journal of dentistry 1997. link